Quantum Dot (QD) can also be called as nanocrystal, and is a nano-particle consisting of Groups II-VI elements or Groups III-V elements. Quantum dots with different emission spectrums can be manufactured by controlling the dimensions of the quantum dots, since the band gaps of the quantum dots are inversely proportional to the dimensions thereof. In addition, the half peak width of the emission spectrum of the quantum dot (approximately 50-60 nm) is narrower than the half peak width of the green phosphor (approximately 80 nm) or the half peak width of the red phosphor (approximately 100 nm); wherein the green phosphor and the red phosphor here are common used in LED at present. Making use of the two characters above, when the quantum dot is applied to television, it can be well used with color filter (CF); in this way, a high transmittance can be achieved and a high gamut (NTSC) can be ensured.
At present, quantum dot materials in the market mainly include CdSe which forms the core of a quantum dot, and CdS which forms the shell of the quantum dot. High temperature and oxygen may lead to an invalidation of the quantum dot materials. Therefore, the quantum dots in the market should have their materials protected. The protection methods can be classified into two types. One is the quantum dot film (QD-film), that is, the quantum dot materials are encapsulated by PET. The other method is the quantum dot rail (QD-rail), that is, the quantum dot materials are encapsulated within a hollow glass tube. The quantum dot film needs larger number of materials; while a great number of quantum dot rails are needed if the backlight in the display field using the quantum dot, since the light emitting angle of the quantum dot rail is limited. These two methods are not cost-effective.